Mo. search focuses on big-box stores, apartments

Lowes Home Improvement employees stand in the parking lot of their store after it was hit by a tornado in Sanford, N.C., Saturday, April 16, 2011. (Jim R. Bounds)

May 24, 2011 12:00:00 AM PDT

JOPLIN, Mo. --

Crews busted holes in concrete slabs and sifted through strewn home goods Tuesday as rescuers focused on crumpled big-box stores and apartment complexes in Joplin in a frantic search for survivors of the deadliest single U.S. twister in about 60 years.